Independent Effect of Custom Paint widget in flutter - custom-painting

When I click on List view item it changes. I want when index changes custom paint effect of previous image save and want to move this paint part only to next widget if user selects apply changes to "yes". When I change by clicking paint and eraser effect remains same which I don't want.
Here is my code:

Related

VBA: Can't change Image Control picture after click on element

Setup
I have an Excel VBA UserForm with an Image Control element. When clicking on buttons in the form, the Image Control's Picture source is set / updated with the following code:
Set MyForm.imgControl.Picture = LoadPicture(pathToFile)
Problem
When the user clicks on the Image Control, updating its Picture source doesn't work anymore. The problem occurs, no matter when in the workflow the Image Control is clicked:
Example 1: User clicks a button to set the Picture (and pictures sets correctly). User clicks on Image Control. User clicks a different button to change the Picture -> displayed picture doesn't change.
Example 2: User clicks on Image Control right after Form load. User clicks on button to change the Picture -> displayed picture doesn't change.
If the user never clicks on the Image Control, everything works perfectly smoothly. It's worth noting that clicking on the Image Control doesn't visibly focus it.
Question
Clicking on the Image Control shouldn't make a difference in whether or not the Picture can be updated or not. How can this be done? Or, at least, does anyone know why the explained behavior is happening, or is it just a bug?
The Control does have Click / MouseDown / ... events (which are empty), but they don't take a Cancel parameter.
It does sound like a bug, as you say, but as a workaround, I'd suggest forcing a repaint after changing the picture:
Set MyForm.imgControl.Picture = LoadPicture(pathToFile)
MyForm.Repaint

How to display show/Hide button in highlight regular mode of NSOutlineView?

How to display show/Hide button in highlight regular mode of NSOutlineView?
I have a grop item at the top of NSOutlineview. I try to display show/hide button in that group item, but I can't find any method to do it. The source list mode can display it but regular mode doesn't.
Is it possible to display show/hide button in highlight regular mode of NSOutlineview?
thanks for helping
This behavior is specific to the source list appearance. There is no public API for getting around this, as it's an intentional enforcement (on Apple's part) of standardized appearances. You could dig around in the headers to look for a way to "hotwire" things, but use of private API bars you from distributing your app through the App Store.
The easier (non-private-API-using) route is to create your own cell view with a borderless button with show/hide title. Use a mouse tracking area (see NSTrackingArea) on the cell view (the superview of your button) to set the button's alpha (via its animator) to fade the button in/out on mouse in/out. Your button would tell the outline view to expand/collapse its cell view's represented item (the easiest way would be to define an outlet to the button via your custom NSView cell view class and configure the button's target/action when the cell view is created for the item).

Adding A View To An Existing View Programatically

How can you add or replace a view within a view with code? I'm programming for OSX, not IOS.
I am using a drawer that utilizes a custom view. In the custom view I have two boxes, one with a custom set of icons that I want to stay static and another box that has the information related to that button. What I want to do is when a user clicks one of the buttons that the 2nd box view changes to reflect the info for that button.
For example, I have five buttons and the default 2nd box is "Info", if the user clicks the 2nd button in the first box view I want to change the 2nd box to be the "List" box instead while the 1st box with the buttons stays intact.
I'm not sure how this would impact constraints since while the first box is a fixed size, the 2nd box needs to be dynamic so that it fills in the "rest of the space" so that when the drawer size changes with the window size that the 2nd box is taking up the remaining real estate.
Thank you!
I have implemented such a scenario in the past using a tabless NSTabView, and an NSSegmentedControl (for the buttons). The NSTabView has it's -takeSelectedTabViewItemFromSender: action connected to the NSSegmentedControl, using Interface Builder.
In the Connections Inspector, this shows up like so:
This has the effect that the index of the selected NSTabViewItem in your NSTabView will correspond to the index of the selected segment in the NSSegmentedControl.

Is control location relative to visible area of form when form has scroll bar?

I have a VB.NET form that dynamically creates a set of controls. If there are too many controls to view on the form, the form will show a scroll bar. (It is an autoscroll form.)
The user can scroll down and click a button which causes the form to change dramatically. It destroys all controls and draws new ones based on user input.
I've noticed that if the user is scrolled to the bottom of the form and click the button, when I destroy and create new controls they aren't located where I want them. It seems to put them relative to the visible portion of the form rather than the top of the top.
Example:
checkbox1.top = 50
checkbox1.left = 15
If the scrollbar is all the way at the bottom, the checkbox should be placed above the visible part of the form. Instead, it is drawn 50 pixels from the top of what I can see.
Please help. How do I make it place the control at an absolute location, rather than being relative to the current position of the scrollbar?
You have to compensate for the scroll position of the container control.
If a panel, then it would look like this:
checkbox1.Top = Panel1.AutoScrollPosition.Y + 50
Alternatively, you could just use a FlowLayoutPanel control, which would handle the placement of the controls for you.

Missing mouse up event from different canvas in smartGWT

I have two canvases located to each other. One is supposed to be a kind of workspace you can add items to, select and rearange them. The other one is just a property view.
What I want to do is to be able to draw a rectrangle on the workspace. As long as the user holds down the mouse button the rectangle will show up. If he releases the button all items that are beneath the rectangle will be selected. This currently works good with the MouseDown, MouseStillDown und MouseUp events. I'm drawing another rectangle shaed canvas on the workspace which will be transformed on every MouseStillDown event and the selection will occur on the MouseUp event. My problem is, that if the user hold down the mouse button and moves it to the property canvas and then releases the button the MouseUp event from the workspace isn't called. Neither is the one from the property since it's missing a MouseDown event. So if the user releases the button there the selection won't work and the rectangle stays in the workspace.
Is there an oppurtunity to somehow avoid this? Or is there a better way to determine the area the user selected with it's mouse while holding down the left mouse button?